Trying to get an image to expand beyond an iframe

Hi, I am playing about with external image galleries, hosted on dropbox, and trying to embed them within a html widget in a hype document. I’m trying to keep the images separate so I don’t weigh hype down. My only problem is that when I try to expand the images, they do expand but won’t expand beyond the iframe - I know this probably a very basic problem but could anyone point me in the right direction?

Are you able to show us the project. Just change you real DBox details.